Miniaturization limitation or speed-up limitation of a semiconductor device including silicon as a base becomes a significant problem. As a method of overcoming the miniaturization limitation, attention has been focused on an application of a layered substance that is ultimately thin conductor, such as graphene, MoS2, WSe2, or SnS2. In such layered substance, a bond between layers is weaker than a bond between atoms in a layer. Therefore, the layered substance can form an intercalation compound including other atoms or molecules between layers. The atoms or molecules taken between layers become dopants that supply electrons or holes to the layered substance. Compared to a dopant that substitutes an atom in a crystal in an existing semiconductor, the dopant present between layers has small scattering effect to electrons or holes, thereby less reducing mobility. Accordingly, the dopant is also advantageous for increasing an operation speed of a semiconductor device.